Stereoselective synthesis of dihydropyrone-containing marine natural products. Total synthesis and structural elucidation of (-)-membrenone-C.

[figure: see text] Three diastereomers of membrenone-C were separately prepared using a common two directional chain extending synthetic strategy. This has established the absolute and relative configuration of the natural product to be as shown in the foregoing graphic. Key steps in the synthesis of all the isomers are a stereoselective aldol coupling and reduction giving the C7-C9 stereocenters, a two direction chain extending double titanium aldol coupling, and the trifluoroacetic acid promoted double cyclization/dehydration giving the two dihydropyrone rings.

A randomized controlled trial of smoking cessation counseling after myocardial infarction.

BACKGROUND: Smoking cessation after myocardial infarction (MI) has been associated with a 50% reduction in mortality but in-hospital smoking cessation interventions are rarely part of routine clinical practice. METHODS: One hundred cigarette smokers consecutively admitted during 1996 with MI were assigned to minimal care or to a hospital-based smoking cessation program. Intervention consisted of bedside cessation counseling followed by seven telephone calls over the 6 months following discharge. Primary outcomes were abstinence rates measured at 6 months and 1 year post-discharge. RESULTS: At follow-up, 43 and 34% of participants in minimal care and 67 and 55% of participants in intervention were abstinent at 6 and 12 months. respectively (P<0.05). Abstinence rates were calculated assuming that participants lost to attrition were smokers at follow-up. Intervention and self-efficacy were independent predictors of smoking status at follow-up. Low self-efficacy combined with no intervention resulted in a 93% relapse rate by 1 year (P<0.01). CONCLUSIONS: A hospital-based smoking cessation program consisting of inpatient counseling and telephone follow-up substantially increases smoking abstinence 1 year after discharge in patients post-MI. Patients with low self-efficacy are almost certain to relapse without intervention. Such smoking cessation programs should be part of the management of patients with MI.