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Abstract: Radicamine B 5 was synthesized from p-hydroxy benzaldehyde 7 stereoselectively using acid catalysed amido cyclisation with the help of neighbouring group participation (NGP). Without NGP both radicamine B 5 and its epimer 5-epi radicamine B 6 were obtained. The key steps of the synthesis are Sharpless asymmetric dihydroxylations and acid mediated amido cyclisation. [Copyright &y& Elsevier]

Abstract: An efficient and highly stereoselective approach to bicyclic aza sugars is described using Grignard reaction on an N-benzyl imine derived from 3-O-benzyl-1,2-O-isopropylidine-α-d-xylo-pentodialdofuranose, ring closing metathesis, and reductive cyclization as key steps. [Copyright &y& Elsevier]

Abstract: The stereoselective synthesis of 6-epi-pentenocin B 3 is described using a stereoselective Grignard reaction and ring-closing metathesis (RCM) as the key steps. [Copyright &y& Elsevier]

Abstract: A short and stereoselective synthesis of (−)-codonopsinol 5 and its C-2 epimer 6 were accomplished from commercially available starting material d-1,5-gluconolactone, using acid mediated amido cyclisation as the key step. The inhibitory activitiy of these compounds against glucosidase and galactosidase has been studied. [Copyright &y& Elsevier]

A versatile and efficient method for the preparation of (2S)-2-(hydroxymethyl)-N-Boc-2,3-dihydro-4-pyridone from l-(−)-phenylalanine 2 utilising the aromatic system as a masked β-keto aldehyde was developed. The key step in the sequence is an intramolecular cyclisation of 6 to give 2,3-dihydropyridin-4-ones. [Copyright &y& Elsevier]

A concise synthesis of (2 R ,4 R )-4-hydroxyproline ( 1 ) and (2 S ,4 S )-4-hydroxyproline ( 2 ) has been developed in enantiomerically pure form from commercially available starting materials with excellent diastereoselectivity. The tightly bound chelation controlled transition state formed during the 5- exo - tet ring closure reaction is assumed to be the origin of high diastereoselectivity. [ABSTRACT FROM AUTHOR]