The tricyclic core of the cylindricine or lepadiformine families of alkaloid natural products was assembled via a Prins addition/intramolecular Schmidt rearrangement under Lewis acid conditions. Both single-pot and two-stage variations of this process were examined, with particular attention to the stereochemical outcome of the processes. This technology has been applied to a formal total synthesis of lepadiformine A and a total synthesis of lepadiformine C.

Protected 4-hydroxycyclopentenones (4-HCPs) constitute an important class of intermediates in chemical synthesis. A route to this class of compound has been developed. Key steps include Noyori reduction (which establishes the stereochemistry of the product), ring-closing metathesis, and simple functional group conversions to provide a set of substituted 4-HCPs in either enantiomeric form.

A new chiral sulfinyl transfer auxiliary derived from readily available phenylglycine was developed. This auxiliary is utilized to synthesize a diverse array of alkyl- and arylsulfinamides and sulfinylferrocenes in high yields and excellent ee's. The desired products are produced in a one-pot sequence from the oxathiazolidine 2-oxide by two sequential nucleophilic additions that proceed in a stereospecific manner.

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Stereodivergent Synthesis of Enantioenriched 4-Hydroxy-2-cyclopentenones. -Using a known pathway, chiral diol (II) can be easily obtained via Noyori reduction which establishes the product stereochemistry in a single step. Following ring-closing metathesis and simple oxidation give access to enantiomerically pure 4-hydroxycyclopentenones (4-HCPs) as valuable building blocks for further syntheses. -(SINGH, G.; MEYER, A.; AUBE*, J.; J. Org. Chem. 79 (2014) 1, 452-458, http://dx.