Dihalomethyl carbinol compounds are not commonly used as intermediates in organic chemistry. Because these dihalomethyl carbinols are valuable synthetic intermediates for the one carbon elongation, the addition of the dihalomethyl lithium to carbonyl compounds have been studied. The resulting dihalomethyl carbinols have been transformed into alpha-hydroxy aldehydes by the participation of neighboring hydroxyl group under the mild basic condition. By using this method, several natural products were synthesized, which include sesquiterpene-based endothelin receptor antagonists, phytuberin, aflatoxin M2 and a tricyclic hydroxy hemiacetal subunit of azadirachtin.