Development of a New Stereospecific Allylation and Its Application for Synthesis

迄今为止，还没有报道过通过乙醛-2-烯基化有效合成同丙烯醇的方法。另一方面，我们最近发现了第一个方便和高度立体选择性的乙醛-2-烯基化反应，这是由于[3.3]-单链重排引起的。此外，我们还证明了利用光学活性薄荷酮作为手性助剂，通过烯丙基转移反应使醛烷-2-烯基化的可能性。我们还发现，由于烷基链的长度增加，这提高了产品的收率。通过烯丙基转移反应使醛的丙二烯基化是一个很有价值的反应，特别是对于不对称合成来说。这一发现使得利用具有光学活性的同丙烯醇有效地合成光学纯的多取代四氢吡喃衍生物成为可能。反过来，它也成为可能，有效地合成许多生物活性化合物及其类似物的光学活性形式。

To date, there have been no reported methods for effectively synthesizing homoallylic alcohols via alk-2-enylation of an aldehyde. On the other hand, we recently discovered the first convenient and highly stereoselective but-2-enylation of an aldehyde via an ally-transfer reaction due to [3.3]-sigmatropy rearrangement. Further, we demonstrated the possibility of alk-2-enylation of an aldehyde via an allyl-transfer reaction using optically active menthone as a chiral auxiliary. We also discovered that this improved the yield of the product due to an increase in the length of the alkyl chains.Prop-2-enylation of an aldehyd via an allyl-transfer reaction is a valuable reaction is a valuable reaction, particularly for asymmetric syntheses. This discovery makes it possible to efficiently synthesize optically pure poly-substituted tetrahydropyrane derivatives using an optically active homoallylic alcohol. In turn, it also becomes possible to efficiently synthesize many bioactive compounds and their analogues in optically active forms.