6,14-endoethenotetrahydrooripavine 6,14-endoethenotetrahydrooripavine 6,14-endoethenotetrahydrooripavine is the central nucleus, or backbone, of a class of morphinan opioids known as the bentley compounds and may be considered their "privileged scaffold". these include but are not limited to etorphine and buprenorphine. they usually have thebaine or oripavine as their precursor in their syntheses (and are thus termed "thevinols" and "orvinols", respectively). 6,14-endoethenotetrahydrooripavine names iupac name (4r,7s,7ar,12br)-7-methoxy-3-methyl-2,3,4,4a,7,7a-hexahydro-1h-4al5-4a,7-ethano-4,12-methanobenzofuroisoquinolin-9-ol identifiers 3d model (jsmol) interactive image pubchem cid 59866315 inchi inchi=1s/c20h23no3/c1-21-10-9-20-15-12-3-4-13(22)16(15)24-17(20)19(23-2)7-5-18(20,6-8-19)14(21)11-12/h3-5,7,14,17,22h,6,8-11h2,1-2h3/t14-,17+,18?,19-,20+/m1/s1 smiles 12oc3=c4c(c5n(c)cc1451cc2(oc)c=c1)=cc=c3o properties chemical formula c20h23no3 molar mass 325.408 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references