Bicyclo decane

Keywords Bicyclo[4.3.1]decanes Biosynthesis Indole alkaloids ... 

A good deal of effort has been devoted to the preparation of derivatives of the cyclohepta[cd]indole and bicyclo[4.3.1]decane ring systems, that can be considered related to the ABC and CD ring systems of welwistatin, respectively, but much of this work cannot be translated easily to methods relevant to welwistatin synthesis. For instance, many successful approaches to the cyclohepta[cd] indole system are based on intramolecular radical cycliza-tions [12] or Heck reactions [13]. In many published examples, a substituent at the indole C-2 avoids the competing reaction at this position, but this device renders the reaction products inadequate to achieve the oxindole struc-... 

The method of Huckin and Weiler has enjoyed widespread use in synthesis. For example, recently reported syntheses of rrans-bicyclo[4.3.1]decan-10-one and a bicyclo[4.4.1]undecan-7-one derivative have employed y-alkylations of 3-keto ester dianions as key steps. This methodology has also been extended to the formation and y-alkylation of dianions of y,8-unsaturated P-keto esters. ... 

The chiral aldehyde 76 was employed as the starting material of intramolecular ene-reaction to prepare chiral bicyclo [4.3.1] decanes [61]. The one-pot Claisen rearrangement of carveol with ethyl vinyl ether in the presence of a catalytic amount of Hg(OAc)2 furnished the aldehyde 76 stereospedfically (Eq. 3.1.50). For the synthesis of stereoselective side chain introduced aldehydes as the starting materials of intramolecular ene-reaction to prepare chiral bicyclo [3.3.1] decanes [61], a one-pot Claisen rearrangement of carveol with ethyl vinyl ether in the presence of a catalytic amount of Hg(OAc)2 stereospecifically furnished the aldehyde 76 (Eq. 3.1.50). 

An efficient route for the construction of chiral bicyclo[4.3.1]decanes (215) has been developed " employing an acid-catalysed intramolecular carbonyl ene reaction see (214) —> (215). Optically active bicyclic lactones have been prepared by a highly diastereo- and enantio-selective ene reaction of cyclopentenes with ethyl glyoxylate. A one-pot allylic amidation which employs the ene reaction of acylnitroso compounds (216) with electron-rich alkenes has been reported see Scheme 52. 

Bicyclo[4.3.1]decane from bicyclo[4.2.2]decane ring... 

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