Robert E. Ireland

A convergent scheme for the synthesis of spiroketals and the synthesis of (±)-chalcogran

Abstract The hetero-Diels-Alder condensation between furanoid and pyranoid exocyclic vinyl ethers establishes the spiroketal system and subsequent oxidative ring contraction leads to 1.6-dioxaspiroalkane carboxylic acids. The latter are useful subunits for polyether antibiotic synthesis.

The facile reduction of methoxyethoxymethyl esters with lithium triethylborohydride

Abstract The use of a methoxyethylmethyl (MEM) ester has been shown to facilitate the selective reduction of that ester function in the presence of other reduceable esters.

Synthesis of chiral subunits for macrolide synthesis: an efficient method for converting spiroketals into open-chain derivatives

Abstract An efficient method for the conversion of the spiroketals 9 , 11 and 15 into open-chain derivatives by thioketal exchange is reported.

The Synthesis12 and Single Crystal X-Ray Structure Determination of 9α-Cyano-19-Nortestosterone

Abstract In connection with work underway in these laboratories on the total synthesis of Pentacyciic. triterpenes; guitable methods were sought for the introduction of angular methyl groups into preiormed polynuclear systems. A method of some generality was recognized in the work ofNagata3 on the organoaluminum catalyzed conjugate addition of cyanide to α,β-unsaturated ketones and subsequent conversion of the resulting cyano group to the desired angular methyl substttuent. The total synthesis of dl-alnusenone reported4a earlier from these laboratories has this synthon as its central feature. Another approach that appeared attractive entailed the 1,6-addition 5 of cyanide to the dienone 1, available from intermediates already in hand.4b