While numbering the carbon chain, if both OH and double bonds are present in the parent chain, where to start the numbering? Share with your friends Share 0 Geetha answered this The preference is for the functional group OH. So the numbering should be given from OH. For ex., OH-CH2-CH2-CH=CH2 1 2 3 4But-3-ene-1-ol 1 View Full Answer