REGIOSELECTIVE ROUTES TO NUCLEOPHILIC OPTICALLY-ACTIVE 2-CARENE AND 3-CARENE SYSTEMS
REGIOSELECTIVE ROUTES TO NUCLEOPHILIC OPTICALLY-ACTIVE 2-CARENE AND 3-CARENE SYSTEMS
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DOI：
10.1021/jo00292a039
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发表时间：
1990-03-02
影响因子：
3.6
通讯作者：
SHI, YJ
中科院分区：
文献类型：
--
作者：
PAQUETTE, LA;ROSS, RJ;SHI, YJ
市售的(+)-3-蒈烯(4)被证明能够有效地转化为乙烯基溴化物28、46和49以及乙烯基锡烷44。这四种化合物都是由(+)-3-壬卡拉烷酮（23）组成的，这是一种光学纯酮，最好是通过4的环氧化，然后是氧环开环，乙酰化，臭氧分解和crcl2促进还原来制备。23在环丙基羰基意义上表现出的烯醇化的强烈倾向被用来有利于进入28和44。值得注意的是，(+)-3-去甲烷酮（45）的甲酰基腙与它的前体酮23的区别在于，它具有高度区域选择性地从可选的α -位置移出的能力。交叉可以合成进入46号和49号。这类化合物的其他化学性质也被介绍，包括到41的路线，到49的乙烯基溴外聚物。这些分子作为亲核试剂的能力与未来在ingenol领域的工作特别相关。举几个涉及28的反应作为这一性质的例子。
Commercially available (+)-3-carene (4) is shown to be capable of efficient conversion to vinyl bromides 28, 46, and 49 and to vinyl stannane 44. All four compounds stem from (+)-3-noncaranone (23), an optically pure ketone best prepared by epoxidation of 4, followed by oxirane ring opening, acetylation, ozonolysis, and CrCl2-promoted reduction. The strong proclivity exhibited by 23 to enolize in the cyclopropyl carbinyl sense is used to advantage to gain entry to 28 and 44. Remarkably, the tosylhydrazone of (+)-3-norcaranone (45) is distinguished from its keton progenitor 23 by its capacity for highly regioselective deportonation from the alternative .alpha.-position. The crossover has made possible synthetic access to 46 and 49. Other chemistry of this class of compounds is also presented, including a route to 41, a vinyl bromide epimeric to 49. Especially relevant to future work in the ingenol area is the ability of these molecules to serve as neucleophiles. Several reactions involving 28 are provided as exemplary of this property.