Going around that end of Brooklyn is really out of the way, although it takes advantage of the bike lane on the Belt Pkway from Queens. There is a Greenway marked out that you can pick up in Queens that will take you through the center of Brooklyn, rather than going around. It is hard to follow though. The NYC Century does part of that route in reverse and even with a turn sheet, map and turn markers is hard to follow.
Brooklyn_Queens_GreenwayGuide.pdf