it has been surprisingly found that the compounds of the present invention provide unexpected strong green and herbal characteristics . in one embodiment of the present invention , the compounds of the present invention are represented by the following structures : those with skill in the art will recognize that some of the compounds of the present invention have a number of chiral centers , thereby providing numerous isomers of the claimed compounds . it is intended herein that the compounds described herein include isomeric mixtures of such compounds , as well as those isomers that may be separated using techniques known to those having skill in the art . suitable techniques include chromatography such as high performance liquid chromatography , referred to as hplc , and particularly gel chromatography and solid phase microextraction , referred to as spme . the compounds of the present invention were prepared with corresponding aldehydes according to the following reaction schemes , the details of which are specified in the examples . the starting materials and catalysts were purchased from aldrich chemical company . the compounds of the present invention , for example , possess the following fragrance notes : 3 - propylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one ( structure iii ) possesses strong green , herbaceous , fresh , clean , natural , floral , and woody notes ; 3 - butylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one ( structure v ) possesses strong fruity , green , herbal , and celery notes ; 3 - butylbicyclo [ 3 . 2 . 1 ] octan - 2 - one ( structure vi ) possesses strong coconut , lactonic , woody , minty , jasmine cis like , anisic , and tuberose notes ; 3 - pentylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one ( structure vii ) possesses strong anisic , fruity , spicy , mossy , herbal , and celery notes ; and 3 - pentylbicyclo [ 3 . 2 . 1 ] octan - 2 - one ( structure viii ) possesses strong sweet , slight anisic , floral , and celery notes . the use of the compounds of the present invention is widely applicable in current perfumery products , including the preparation of perfumes and colognes , the perfuming of personal care products such as soaps , shower gels , and hair care products , fabric care products as well as air fresheners and cosmetic preparations . these compounds can also be used to perfume cleaning agents , such as , but not limited to detergents , dishwashing materials , scrubbing compositions , window cleaners and the like . in these preparations , the compounds of the present invention can be used alone or in combination with other perfuming compositions , solvents , adjuvants and the like . the nature and variety of the other ingredients that can also be employed are known to those with skill in the art . many types of fragrances can be employed in the present invention , the only limitation being the compatibility with the other components being employed . suitable fragrances include but are not limited to fruits such as almond , apple , cherry , grape , pear , pineapple , orange , strawberry , raspberry ; musk ; and flower scents such as lavender - like , rose - like , iris - like , carnation - like . other pleasant scents include herbal and woodland scents derived from pine , spruce and other forest smells . fragrances may also be derived from various oils , such as essential oils , or from plant materials such as peppermint , spearmint and the like . a list of suitable fragrances is provided in u . s . pat . no . 4 , 534 , 891 , the contents of which are incorporated by reference as if set forth in its entirety . another source of suitable fragrances is found in perfumes , cosmetics and soaps , second edition , edited by w . a . poucher , 1959 . among the fragrances provided in this treatise are acacia , cassie , chypre , cyclamen , fern , gardenia , hawthorn , heliotrope , honeysuckle , hyacinth , jasmine , lilac , lily , magnolia , mimosa , narcissus , freshly - cut hay , orange blossom , orchid , reseda , sweet pea , trefle , tuberose , vanilla , violet , wallflower , and the like . olfactory acceptable amount is understood to mean the amount of a compound in a perfume composition . the compound will contribute its particular olfactory characteristics , but the olfactory effect of the perfume composition will be the sum of the effects of each of the perfumes or fragrance ingredients . thus the compounds of the invention can be used to alter the aroma characteristics of a perfume composition , or by modifying the olfactory reaction contributed by another ingredient in the composition . the amount will vary depending on many factors including other ingredients , their relative amounts and the effect that is desired . the amount of the compounds of the present invention employed in a fragrance formulation varies from about 0 . 005 to about 70 weight percent , preferably from 0 . 005 to about 10 weight percent , more preferably from about 0 . 5 to about 8 weight percent , and even more preferably from about 1 to about 7 weight percent . those with skill in the art will be able to employ the desired amount to provide desired fragrance effect and intensity . in addition to the compounds of the present invention , other materials can also be used in conjunction with the fragrance formulation . well known materials such as surfactants , emulsifiers , polymers to encapsulate the fragrance can also be employed without departing from the scope of the present invention . when used in a fragrance formulation this ingredient provides green and herbal notes that make the fragrance formulation more desirable and noticeable and add the perception of value . all of the odor qualities found in this material assist in beautifying and enhancing the finished accord improving the performance of the other materials in the fragrance . there is also the fruity side of it which is found in many fragrances today which happens to be very trendy , especially for the younger consumers . the following are provided as specific embodiments of the present invention . other modifications of this invention will be readily apparent to those skilled in the art . such modifications are understood to be within the scope of this invention . the chemical materials used in the preparation of the compounds of the present invention are commercially available from aldrich chemical company . as used herein all percentages are weight percent unless otherwise noted , ppm is understood to stand for parts per million , l is understood to be liter , ml is understood to be milliliter , kg is understood to be kilogram , and g be gram . iff as used in the examples is understood to mean international flavors & amp ; fragrances inc ., new york , n . y ., usa . preparation of 2 - propylbicyclo [ 2 . 2 . 1 ] hept - 5 - ene - 2 - carbaldehyde : a 5 - l flask fitted with an overhead stirrer and a condenser was charged with di - n - butylamine ( 75 g ) and acetic acid ( 70 g ). formaldehyde solution in water ( 1 . 3 l , 37 %) was added and the resulting solution was heated to 50 ° c . with stirring . pentanal ( 1 kg ) was then fed in over about 2 hours . after the feed was completed the temperature was maintained at 50 ° c . for 1 hour and then cooled to room temperature . the reaction mixture was poured into a separatory funnel . the organic layer was washed with water and purified by distillation to yield 2 - methylene pentanal ( 820 g ). 2 - methylene pentanal ( 302 g ) and dicyclopentadiene ( 244 g ) were loaded into a 2 - l autoclave . the autoclave was sealed and heated to 170 ° c . the reaction was monitored by gas chromatography (“ gc ”) analysis , which showed the completion after 3 hours . the reaction was cooled to room temperature . the crude product was purified by distillation to yield 2 - propylbicyclo [ 2 . 2 . 1 ] hept - 5 - ene - 2 - carbaldehyde ( 136 g ). 1 h nmr ( cdcl 3 , 500 mhz ): 0 . 90 ppm ( t , 3h , j = 7 hz ), 1 . 48 ppm ( q , 2h , j = 7 . 5 hz ), 2 . 22 ppm ( t , j = 7 . 5 hz ), 5 . 99 ppm ( s , 1h ), 6 . 24 ppm ( s , 1h ), 9 . 54 ppm ( s , 1h ). 1 h nmr ( cdcl 3 , 500 mhz ): 0 . 84 ppm ( t , 3h , j = 7 . 2 hz ), 1 . 11 - 1 . 39 ppm ( m , 6h ), 1 . 49 - 1 . 57 ppm ( m , 1h ), 2 . 16 ppm ( m , 1h ), 2 . 85 ppm ( s , 1h ), 2 . 93 ppm ( s , 1h ), 6 . 07 ppm ( dd , 1h , j = 5 . 37 , 3 . 13 hz ), 6 . 27 ppm ( dd , 1h , j = 5 . 33 , 3 . 08 hz ), 9 . 70 ppm ( s , 1h ). ( alcl 3 , 110 g ) was suspended in toluene ( 1 l ) and chilled to − 30 ° c . using a dry ice / isopropanol bath . 2 - propylbicyclo [ 2 . 2 . 1 ] hept - 5 - ene - 2 - carbaldehyde ( 136 g , synthesized as above ) was fed in using an addition funnel over 1 hour while the temperature was maintained at − 30 ° c . after the feed was completed the temperature was allowed to rise to 0 ° c . gc analysis showed the reaction was completed after 40 minutes . the reaction mixture was then poured onto h 2 so 4 ( 1 l , 20 %) over ice . the resulting biphasic mixture was shaken to split the organic and aqueous layers . the aqueous layer was washed once with toluene ( 300 ml ) and combined with the organic layers . the mixture was then washed with naoh solution ( 750 ml , 10 %), followed by water until the water was tested neutral . the resulting organic material was purified by distillation to yield 3 - propylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one ( 92 g ). 1 h nmr ( cdcl 3 , 500 mhz ): 0 . 87 ppm ( t , 3h , j = 7 . 2 hz ), 1 . 16 - 1 . 37 ppm ( m , 3h ), 1 . 44 - 1 . 50 ppm ( m , 1h ), 1 . 72 - 1 . 81 ppm ( m , 1h ), 1 . 83 - 2 . 00 ppm ( m , 2 / 3h ), 2 . 12 - 2 . 4 ppm ( m , 2h ), 2 . 38 - 2 . 52 ppm ( m , 1h ), 2 . 64 - 2 . 70 ppm ( m , 1 / 3h ), 2 . 77 - 2 . 86 ( m , 1h ), 3 . 00 - 3 . 06 ppm ( m , 1h ), 5 . 80 ppm ( dd , 2 / 3h , j = 5 . 4 , 3 . 1 hz ), 6 . 05 ppm ( dd , 1 / 3h , j = 5 . 7 , 2 . 9 hz ), 6 . 21 - 6 . 26 ppm ( m , 1h ). 3 - propylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one , possessed strong green , herbaceous , fresh , clean , natural , floral , and woody notes . preparation of 2 - butylbicyclo [ 2 . 2 . 1 ] hept - 5 - ene - 2 - carbaldehyde : a 5 - l flask fitted with an overhead stirrer and a condenser was charged with di - n - butylamine ( 77 g ) and acetic acid ( 72 g ). formaldehyde solution in water ( 1 . 1 l , 37 %) was added and the resulting solution was heated to 50 ° c . with stirring . hexanal ( 1 kg ) was then fed in over about 2 hours . after gc analysis showed the completion of the reaction , the reaction mixture was cooled to room temperature , poured into a separatory funnel , and washed once with hcl solution ( 5 %). the organic layer was then washed with saturated sodium bicarbonate to provide crude 2 - methylene hexanal ( 727 g ), which was loaded into a 2 - l stainless steel pressure reactor along with dicyclopentadiene ( 511 g ). the pressure reactor was sealed and heated to 170 ° c . with stirring for two hours . the reaction was then cooled to room temperature . the resulting crude product was purified by distillation to yield 2 - butylbicyclo [ 2 . 2 . 1 ] hept - 5 - ene - 2 - carbaldehyde ( 570 g ). preparation of 3 - butylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one ( structure v ): 2 - butylbicyclo [ 2 . 2 . 1 ] hept - 5 - ene - 2 - carbaldehyde ( 570 g , synthesized as above ) was loaded into a 3 - l round bottom flask fitted with an overhead stirrer and a condenser , followed by methylene chloride ( ch 2 cl 2 , 1 l ). the resulting solution was cooled to − 50 ° c . using a dry ice bath . anhydrous aluminum chloride ( alcl 3 , 215 g ) was then added in one portion . the light yellow solution changed color to orange , then dark red with a simultaneous increase in reaction temperature , up to about − 30 ° c . the reaction temperature was allowed to gradually increase to 15 ° c . gc analysis showed the completion of the reaction after 1 hour . the reaction mixture was then poured onto ice and sulfuric acid ( 10 %), and the organic layers were separated and washed once with sodium hydroxide solution ( 10 %). the solvent ( ch 2 cl 2 ) was removed under reduced pressure , and the resulting crude product was purified by distillation to yield 2 - butylbicyclo [ 2 . 2 . 1 ] oct - 6 - en - 2 - one ( 224 g ). 1 h nmr ( cdcl 3 , 500 mhz ): 0 . 88 ppm ( t , 3h , j = 7 . 03 hz ), 1 . 18 - 1 . 38 ppm ( m , 5h +˜ 20 % of 1h ), 1 . 44 - 1 . 50 ppm ( m , ˜ 80 % of 1h ), 1 . 75 - 1 . 85 ( m , ˜ 80 % of 1h ), 1 . 84 ppm ( d , 1h , j = 11 . 1 hz ), 1 . 94 - 1 . 99 ppm ( m , ˜ 80 % of 1h ), 2 . 12 - 2 . 25 ppm ( m , ˜ 20 % of 3h ), 2 . 39 - 2 . 52 ( m , 1h ), 2 . 64 - 2 . 71 ( m , ˜ 80 % of 1h ), 2 . 77 - 2 . 88 ppm ( m , 1h ), 3 . 00 - 3 . 07 ppm ( m , 1h ), 5 . 78 - 5 . 82 ppm ( m , ˜ 20 % of 1h ), 6 . 02 - 6 . 07 ppm ( dd , ˜ 80 % of 1h , j = 5 . 29 , 2 . 82 hz ), 6 . 19 - 6 . 28 ppm ( dd , 1h , j = 5 . 55 , 2 . 65 hz ). preparation of 3 - butylbicyclo [ 3 . 2 . 1 ] octan - 2 - one ( structure vi ): 3 - butylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one ( 100 g , synthesized as above ) was placed in a stainless steel autoclave with isopropanol ( 50 g ) and palladium on carbon ( pd / c , 1 g ). the mixture was placed under 300 psi of hydrogen gas ( h 2 ) and heated at 100 ° c . until gas uptake ceased . the resulting material was removed from the autoclave , filtered , and distilled to yield 3 - butylbicyclo [ 3 . 2 . 1 ] octan - 2 - one ( 55 g ). 1 h nmr ( cdcl 3 , 500 mhz ): 0 . 99 ppm ( t , 3h , j = 7 . 11 hz ), 1 . 11 - 1 . 34 ppm ( m , 6h ), 1 . 65 - 1 . 75 ppm ( m , 3h ), 1 . 76 - 1 . 88 ppm ( m , 3h ), 1 . 90 - 2 . 02 ppm ( m , 2h ), 2 . 24 - 2 . 34 ppm ( m , 1h ), 2 . 39 - 2 . 44 ppm ( m , 1h ), 2 . 70 - 2 . 74 ppm ( m , 1h ). 3 - butylbicyclo [ 3 . 2 . 1 ] octan - 2 - one possessed strong coconut , lactonic , woody , minty , jasmine cis like , anisic , and tuberose notes . preparation of 2 - pentylbicyclo [ 2 . 2 . 1 ] hept - 5 - ene - 2 - carbaldehyde : a 3 - l three - neck flask fitted with an overhead stirrer and a condenser was charged with di - n - butylamine ( 33 g ) and acetic acid ( 31 g ). formaldehyde solution in water ( 500 ml , 33 %) was added and the resulting solution was heated to 50 ° c . with stirring . heptanal ( 500 g ) was fed in over about 1 . 5 hours . a slight exotherm was noticed during the feed . gc analysis showed the consumption of heptanal and the production of 2 - methylene heptanal , and a conversion rate of about 95 % after the feed was completed . the reaction was cooled to room temperature and the reaction mixture was poured into a separatory funnel and washed once with hcl solution ( 5 %). the organic layer was then washed once with saturated sodium carbonate to provide crude 2 - methylene heptanal ( 553 g ), which was loaded into a 2 - l stainless steel pressure reactor along with dicyclopentadiene ( 343 g ). the pressure reactor was sealed and heated to 170 ° c . with stirring for two hours . the reaction was then cooled to room temperature . the resulting crude product was purified by distillation to yield 2 - pentylbicyclo [ 2 . 2 . 1 ] hept - 5 - ene - 2 - carbaldehyde ( 217 g ). preparation of 3 - pentylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one ( structure vii ): 2 - pentylbicyclo [ 2 . 2 . 1 ] hept - 5 - ene - 2 - carbaldehyde ( 217 g , synthesized as above ) was loaded into a 2 - l round bottom flask fitted with an overheard stirrer and a condenser , followed by ch 2 cl 2 ( 1 l ). the resulting mixture was cooled to 0 ° c . using a dry ice bath . alcl 3 ( 153 g ) was then added in one portion . after gc analysis showed the completion of the reaction , the reaction mixture was poured onto ice , and the organic layers were separated and washed once with sodium hydroxide solution ( 10 %). the solvent ( ch 2 cl 2 ) was then removed under reduced pressure , and the resulting crude product was purified by distillation to yield 3 - pentylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one ( 100 g ). 1 h nmr ( cdcl 3 , 500 mhz ): 0 . 87 ppm ( t , 3h , j = 7 . 05 hz ), 1 . 16 - 1 . 36 ppm ( m , 8h ), 1 . 76 - 1 . 83 ppm ( m , 1h ), 2 . 11 - 2 . 24 ppm ( m , 3h ), 2 . 44 - 2 . 50 ppm ( m , 1h ), 2 . 78 ( s , 1h ), 3 . 05 ppm ( t , 1h , j = 3 . 69 hz ), 5 . 80 ppm ( dd , 1h , j = 5 . 12 , 3 . 31 hz ), 6 . 24 ( dd , 1h , j = 5 . 29 , 2 . 91 hz ). 3 - pentylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one possessed strong anisic , fruity , spicy , mossy , herbal , and celery notes . preparation of 3 - pentylbicyclo [ 3 . 2 . 1 ] octan - 2 - one ( structure viii ): 3 - pentylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one ( 130 g , synthesized as above ) was placed in a stainless steel autoclave with isopropanol ( 30 g ) and pd / c ( 1 . 5 g ). the mixture was placed under 300 psi of hydrogen gas , and heated at 100 ° c . until gas uptake ceased . the resulting material was then removed from the autoclave , filtered , and distilled to yield 3 - pentylbicyclo [ 3 . 2 . 1 ] octan - 2 - one 70 g ). 1 h nmr ( cdcl 3 , 500 mhz ): 0 . 88 ppm ( t , 3h , j = 6 . 89 hz ), 1 . 10 - 1 . 18 ppm ( m , 1h ), 1 . 19 - 1 . 37 ppm ( m , 7h ), 1 . 65 - 1 . 89 ppm ( m , 6h ), 1 . 90 - 2 . 03 ppm ( m , 2h ), 2 . 25 - 2 . 34 ppm ( m , 1h ), 2 . 41 - 2 . 45 ppm ( m , 1h ), 2 . 73 ppm ( t , 1h , j = 5 . 62 hz ). the fragrance properties of the above compounds ( i . e ., structures ii - vii ) were evaluated using an intensity scale of 0 to 3 , where 0 = none , 1 = weak , 2 = moderate , 3 = strong . averaged sensory scores were reported in the following : compound nos . 1 - 5 ( i . e ., structures iii , v , vi , vii , and viii ) exhibited unexpected strong and long - lasting odor , superior to compound no . 6 , which contains a hexyl group , and compound no . 7 , which contains a heptyl group . 3 - propylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one imparts green , herbaceous , fresh , clean , natural , floral , and woody characters to a fragrance formula . 3 - butylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one imparts fruity , green , herbal , and celery characters to a fragrance formula . 3 - pentylbicyclo [ 3 . 2 . 1 ] oct - 6 - en - 2 - one imparts anisic , fruity , spicy , mossy , herbal , and celery characters to a fragrance formula .