Not sure what you are asking about. With begin ... end, you also get an AST you can work with. I am assuming you want to skip or customize begin?
I came to Julia from Common Lisp, as first I was missing the equivalent of
(somemacro (header arguments)
followed by
body)
but now I think that begin is not that much of a hassle and keeps the code readable. This is one of the trade-offs between using S-expressions (nice for macros) and and Algol-like syntax (which can be very compact with various special operators, like in Julia).
In addition to potentially being confusing to someone who did not read the docs/source for a particular macro, constructs like somebegin would require editor indentation macros to parse and understand macro definitions.