INTRAMOLECULAR SIMMONS-SMITH REACTION AND OTHER SYNTHETIC ALTERNATIVES TO CYCLOPROPANATION OF DIENIC DIAZOKETONES - PARALLEL DECOMPOSITION PATHWAYS OF A STERICALLY CONGESTED DIAZOKETONE AND ITS VINYLCYCLOPROPANE UNDER THERMAL, PHOTOLYTIC, ACID-CATALYZED, AND RADICAL-RELEASE CONDITIONS
INTRAMOLECULAR SIMMONS-SMITH REACTION AND OTHER SYNTHETIC ALTERNATIVES TO CYCLOPROPANATION OF DIENIC DIAZOKETONES - PARALLEL DECOMPOSITION PATHWAYS OF A STERICALLY CONGESTED DIAZOKETONE AND ITS VINYLCYCLOPROPANE UNDER THERMAL, PHOTOLYTIC, ACID-CATALYZED, AND RADICAL-RELEASE CONDITIONS
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DOI：
10.1021/jo00201a026
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发表时间：
1985-01-01
影响因子：
3.6
通讯作者：
SRNAK, A
中科院分区：
文献类型：
--
作者：
HUDLICKY, T;RANU, BC;SRNAK, A
0试剂：⑴ CH 2CHMgBr/THF;（ii）RCH 2C（OEt）3/+;（iii）KOH/H2O;（iv）（CH 3）2CHCOCl/Et3N，然后LDA/THF（-78 ℃-25 ℃）;（v）LDA，THF/MeI;（vi）（COCl）2/苯;（vii）CH 2N2/Et2O。在等式1中，2我们假设，将该方法的闭环顺序颠倒应用于等式2中描述的重氮酮1，最终将导致含有必要的环A的三环酮2的氧合，以最终加工成柯黎林。在过去的几年中，我们已经发展了一种可靠的分子内环化环戊烯的方法，通过环丙烷化-环戊烯重排3或二烯重氮酮的酸催化分解4。我们特别感兴趣的是测试二卤化物如6（图II）的顺序自由基释放的条件，预期在酸催化条件下直接平行于重氮酮的行为的两个连续的碳-碳键形成步骤。由于文献中包含了使用R3 SnH/AIBN系统5或光解6通过烯烃与卤化物的相互作用引起的自由基封闭的例子，因此外推到二烯-偕-二卤化物系统似乎是合乎逻辑的。重氮酮1和环丙烷7的环戊烯部分含有不利的空间位阻，并且由于拥挤的乙烯基环丙烷重排为环戊烯倾向于缓慢，8我们曾希望测试在这些基底上形成碳-碳键的替代方法。在本文中，我们报告了这种重氮酮及其衍生物在各种条件下的平行行为。重氮酮1的制备如图I所示。二甲基化的二烯酸5c是通过在爱尔兰开发的条件下，应用由醇4的异丁酸酯衍生的烯醇阴离子的Claisen重排7或通过由4在正三乙基原丙酸酯中重排获得的单甲基酸5 b的酯的甲基化（LDA/Mel）来制备的
0 Reagents:(i) CH2CHMgBr/THF;(ii) RCH2C (OEt) 3/+/;(iii) KOH/HjO;(iv)(CH3) 2CHCOCl/Et3N, then LDA/THF (-78 C- 25 C);(v) LDA, THF/Mel;(vi)(COCl) 2/benzene;(vii) CH2N2/Et20. in eq l. 2We assumed that the reversal of the order of the ring-closing sequence of this methodology appliedto the diazoketone 1 depicted in eq 2 would eventually lead to the tricyclic ketone 2 containing thenecessary ring A ox-ygenation for eventual elaboration to coriolins. During the pastfew years, we have developed a reliable method of intramolecular cyclopentene annulation via the cyclopropanation-cyclopentene rearrangement3 or the acid-catalyzed decomposition4 of dienicdiazoketones. We were especially interested in testing the conditions of se-quential radical release of dihalides such as 6 (Chart II) anticipating two consecutive carbon-carbon bond forming steps in direct parallelto the behavior of diazoketones under the conditions of acid catalysis. Since the literature contained examples of radical closures elicited by the interaction of olefins with halides using the R3SnH/AIBN system5 or photolysis, 6 theextrapolation to a diene-gem-inal dihalide system seemed a logical one. The cyclopentene portion of diazoketone 1 and cyclopropane 7 contains unfavorable steric disposition, and since the re-arrangements of congested vinylcyclopropanes to cyclopentenes tend to be sluggish, 8 we had hoped to test alternate methods of carbon-carbon bond formation on these substrates. In this paper we report on the parallel behavior of this diazoketone and its derivatives under a variety of conditions.Diazoketones 1 were prepared as outlined in Chart I. The dimethylated dienic acid 5c was prepared by the ap-plication of Claisen rearrangement of the enolate anion derived from the isobutyrate of alcohol 4 under conditions developed by Ireland7 or by the methylation (LDA/Mel) of the ester of the monomethyl acid 5b obtained by the rearrangement of 4 in refluxing triethyl orthopropionate