with a silylating agent and a fluoride ion catalyst cyclizing agent or, when B is a deprotonated chiral auxiliary as defined above, with a silylating agent and a salt of said chiral auxiliary, provided that where substituents A, D, {HEAD ~ Q}, R, R1 and R2 include substituents selected from the group consisting of {TAIL ~ NH2}, SH and OH, said substituents are suitably protected prior to reaction with the silylating agent 
with a silylating agent and a fluoride ion catalyst cyclizing agent or , when B is a deprotonated chiral auxiliary as defined above , with a silylating agent and a salt of said chiral auxiliary , provided that where substituents A , D , { HEAD ~ Q } , R , R1 and R2 include substituents selected from the group consisting of { TAIL ~ NH2 } , SH and OH , said substituents are suitably protected prior to reaction with the silylating agent
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH