<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gimisis, Thanasis</style></author><author><style face="normal" font="default" size="100%">Koreeda, Masato</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">{A HIGHLY EFFICIENT SYNTHESIS OF 3-METHYLCHOLANTHRENE}</style></title><secondary-title><style face="normal" font="default" size="100%">J. Org. Chem.</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1993</style></year><pub-dates><date><style  face="normal" font="default" size="100%">dec</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://pubs.acs.org/doi/abs/10.1021/jo00077a045</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">25</style></number><volume><style face="normal" font="default" size="100%">58</style></volume><pages><style face="normal" font="default" size="100%">7158–7161</style></pages><isbn><style face="normal" font="default" size="100%">0022-3263</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A five-step synthesis of 3-methylcholanthrene (1) has been achieved starting from 5-methylhomophthalic anhydride and N,N-diethyl-1-naphthamide in 55{%} over all yield. Treatment of a solution of the preformed lithium enolate of 5-methylhomophthalic anhydride (3) with an equimolar solution of 2-lithio-1-naphthamide (4), followed by acid hydrolysis, provides cleanly the spirobislactone 5 in 80{%} overall yield. In addition, the synthesis features a unique, highly selective double Friedel-Crafts cyclization of the aryl diacid 2 with PPA to give rise, after acetylation, to keto acetate 6.</style></abstract></record></records></xml>