
TY  - JOUR
A1  - Collins, DJ 
A1  - Cullen, JD 
T1  - The Structure and Function of Estrogens. IX. Synthesis of the <I>trans</I> Isomer of 5,5,10b-Trimethyl-4b,5,6,10b,11,12-hexahydrochrysene-2,8-diol
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1988
VL  - 41
IS  - 5
SP  - 735
EP  - 744
KW  - 
UR  - https://doi.org/10.1071/CH9880735 
N2  - Alkylation of ketene methyl trimethylsilyl acetal (10) with 1&#958;-acetoxy- 6-methoxy-2-(p- methoxyphenyl )-2-methyl-1,2,3,4-tetrahydronaphthalene (9) in the presence of zinc iodide gave 84% of methyl (1&#8242;RS,2&#8242;RS)-2- [6&#8242;-methoxy-2&#8242;-(p-methoxyphenyl )-2?-methyl-1&#8242;,2&#8242;,3&#8242;,4&#8242;- tetrahydronaphthalen-1&#8242;-yl] ethanoate (11a). Cyclization of the derived acid (11b) with methanesulfonic acid gave 89% of 2,8-dimethoxy-10b-methyl-cis-4b,10b,11,12-tetrahydrochrysen-6(5H)-one (12a), Clemmensen reduction of which afforded 52% of 2,8-dimethoxy-4b-methyl-cis- 4b,5,6,10b,11,12-hexahydrochrysene (12b). Oxidation of (12b) with dichlorodicyanobenzoquinone gave 70% of the conjugated enone (4), which upon hydrogenation over 10% palladium/charcoal gave a 5:1 ratio of 2,8-dimethoxy-10b-methyl-trans-4b,10b,11,12-tetrahydrochrysen-6(5H)-one (14) and the cis isomer (12a). Exhaustive methylation of the trans ketone (14) yielded 49% of 2,8-dimethoxy-5,5,10b-trimethyl-trans-4b,10b,11,12-tetrahydrochrysen-6(5H)-one (16), which upon Clemmensen reduction followed by O- demethylation afforded 5,5,10b-trimethyl-trans-4b,5,6,10b,11,12-hexahydrochrysene-2,8-diol(2). 
ER  -

